The invention relates to an improved mechanical assembly to accomplish sudden interlocking and unlocking of a translation switch. This assembly allows for automatic reinforcement after interlocking and before re-interlocking of the switch.
The main purpose of this mechanical assembly is to provide improvements in the field of switches for industrial use, having translation contact movement.
Translation switches are valued for their short circuit bearing current because they have the important advantage of possessing a lateral contact supply between the two clamps, in the manner of pliers.
This characteristic assures perfect contact, true and complete from the beginning of engagement of the two pieces, and suppresses rebounds and flutter found with other types of contacts during peak currents.
For security purposes, those switches have been provided with interlocking and unlocking actuating mechanisms, the principal characteristics of which were to decrease manual force to be exerted on the handle that causes reinterlocking.
Numerous spring mechanisms provide for sudden interlocking and unlocking. For instance, there are mechanisms described in the Canadian Pat. No. 601,653 TURNER, and in the following U.S. Pat. Nos.: 2,995,043 LUSK, 3,614,358 HERMANN, 3,621,189 LINK, 4,146,765 WILSON, 4,166,205 MAIER, 4,219,713 MAIER and RICCI, where a combination of return forces of various springs renders it possible to obtain fast release of energy for a sudden interlocking or unlocking.
But, in most of them, it is a question of interlocking or unlocking the respective switches by a rotary motion for which the application of spring action is facilitated by the use of pivoting levers.
These complex mechanisms are costly to manufacture and to install and do not produce efficient performance which is sought after.
Other embodiments utilize mechanisms comprising an elbow or toggle joint or similar devices. For instance, German Pat. No. 601429 Anton WORNER, French Pat. Nos. 1,137,406 THOMSON-HOUSTON, 1,542,042, ELLENBERGER, and U.S. Pat. Nos. 2,794,881 FRANK, 3,187,593 MAC CLOUD, 3,796,845 SCHIRAE.
In those embodiments, spring compression between the initial position and the mid point causes abrupt seesaw motion towards the opposite position.
Even though this type of mechanism, when applied to a lateral displacement switch, makes it possible to benefit from all advantages of this type of switch, it nevertheless exhibits, besides the disadvantages of purely manually operated switch needing a certain effort for its operation, a limited performance insufficient in certain cases of use.
In fact, only the transverse component of the elastic force of the spring can be exploited for the seesaw motion. Yet, this transverse component has only a small part of its total value in the neighborhood of the dead center.
Consequently, those switches have an interlocking or unlocking speed limited by the inherent characteristics of this type of mechanism. Moreover, this type of switch cannot be provided with a remote control unlocking device because of the considerable control energy which would have to be used to rotate this mechanism.
Furthermore, devices exist allowing for collapsing an alignment of several pivoting axles of pushing or return mechanisms. Those devices are called toggle joint mechanisms. Two embodiments are described in U.S. Pat. Nos. 2,580,511 BRANCHU and 3,754,108 MAROT. Those devices comprise two main parts connected to each other and each joined at one of its extremities to a part of a mechanism in which the toggle joint mechanism is inserted. Equilibrium position corresponds to the alignment of those axes. An unlocking lever causes those axes to become misaligned, thus causing the collapse, that is, the opening by lateral displacement.
Remote control switches also exist, such as that described in French Pat. No. 1,137,406 THOMSON HOUSTON in which an electromagnetic coil retains a blocking lock of a complex mechanism having an elbow or toggle joint, the speed of movements of which, however, is not guaranteed.